ISSN

Number 47 | June 2016

Interactive Digital Resources for a Blended

Learning Controls Course

Ana Maria Beltran Pavani

William de Souza Barbosa

Internal Research Reports

Number 47 | June 2016

Interactive Digital Resources for a

Blended Learning Controls Course

Ana Maria Beltran Pavani

William de Souza Barbosa

CREDITS

Publisher:

MAXWELL / LAMBDA/CCPA/VRAc

Sistema Maxwell / Laboratório de Automação de Museus, Bibliotecas Digitais e Arquivos

http://www.maxwell.vrac.puc-rio.br/

Organizers:

Alexandre Street de Aguiar

Delberis Araújo Lima

Cover:

Ana Cristina Costa Ribeiro

Interactive Digital Resources for a Blended Learning Controls Course

Ana M. B. Pavani*, Member IEEE. William S. Barbosa**

Pontifícia Universidade Católica do Rio de Janeiro, Rio de Janeiro, RJ, 22451-900

Brazil

*(e-mail: apavani@puc-rio.br). **(e-mail: wsbarbosa@ele.puc-rio.br)

Abstract: This paper presents the digital resources used in an undergraduate blended learning Controls course that is mandatory in the curricula of both Controls and Automation Engineering and Electrical

Engineering. It briefly describes available items – texts, videos, online exercises, simulators and other

assorted types of contents that substitute for class hours. The objective of blended learning and of the use

of online resources is to stimulate self learning so that the sessions are used for discussion and problem

solving.

Keywords: b-learning; learning objects; simulators; interactive learning; control systems

1. INTRODUCTION

The faculty of Electrical Engineering of Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio) has been

very active in using ICT – Information and Communication

Technology tools to support traditional face-to-face courses.

This has been going on for two decades. In the first semester

of 2014, two courses started being taught in the blended

learning mode (b-learning) – Signals & Systems and Electric

& Electronic Circuits. In the second semester, the Controls &

Servomechanisms course was switched to this mode. Even before adopting b-learning, abundant online courseware was

available from the Maxwell System

(http://www.maxwell.vrac.puc-rio.br/), the integration an

Institutional Repository (IR) with a Learning Management

System (LMS); part of the courseware was interactive. The

introduction of b-learning was a motivation to keep

developing contents of the same types and to add new

interactive resources. The new resources for the b-learning

courses were introduced in the first semester of 2015.

Controls & Servomechanisms is a mandatory course in the curricula of Controls and Automation, and Electrical

Engineering. It is taught every term with an average of 15

students per term. Before switching to b-learning, it had 8

hour per week of traditional face-to-face classes – 6 lecture

and 2 laboratory hours. The b-learning option substituted computer mediated activities and home assignments for 2

lecture hours.

This work presents the courseware that has been developed

for b-learning. It also mentions other resources that have been in use since ICT supported learning was introduced to

enhance the traditional face-to-face mode.

Section 2 addresses the initial digital resources while section

3 deals with the new interactive courseware. Section 4 presents the b-learning mode and the use of the new

resources for the first time (second semester of 2015).

Section 5 comments the results, current activities and actions

to be taken in the near future. Finally, section 6 outlines the

demo and access numbers.

2. COURSEWARE DEVELOPED AND USED BEFORE

2015

At the very beginning, due to the technological limitations in the second half of the 1990s, courseware was made up of two

sets of resources – hypertext files with some images and the

corresponding text files for linear navigation.

In the early 2000s, small videos, animations and simulators were introduced. The simulators allowed some interactivity.

At the same time, online exercises started being developed –

each had, at least, three parameters and/or functions sets and

one was randomly selected every time the exercise was used; online check and suggested solutions were available too.

Exercises were in Electric & Electronic Circuits, Control

Systems and Signals & Systems.

In 2008, the numbers of exercises in the three topics had grown a lot and some organization was necessary. The

exercises were organized in three interactive books, one for

each subject; they are offered as a collection entitled

Exercícios Interativos em Engenharia Elétrica (Interactive

Exercises in Electrical Engineering).

The books do not contain texts, only interactive exercises. They maintain the characteristic of having at least three

options of parameters and/or functions that are randomly

selected each time the exercise is used. They also offer online

checking and suggested solutions. The exercises are grouped

in chapters that are the usual in text books in each area. The

total numbers of exercises are: Electric & Electronic Circuits

– 281; Controls & Servomechanisms – 237; and Signals &

Systems – 167. They are in open access and can be found at

http://www.maxwell.vrac.puc-rio.br/livros/index.html. Figure 1 shows screen shots of the interactive books.

Fig. 1. Interactive books in Electrical Engineering cover,

interactive book in Controls & Servomechanisms cover and

two exercises.

In parallel, a set of class notes (5 volumes), a study guide and lists of assignments have been created. These are text files.

In 2012, a series of resources was started – Objetos

Educacionais em Engenharia Elétrica (Learning Objects in

Electrical Engineering). Each one is a stand alone content; they are in different areas of EE. They are of varied nature –

simulators, animations, small videos and other hypermedia.

Currently, there are 44 such objects. Among them, 28 are

related to Controls, though they can be used in other courses

too. The Learning Objects in EE can be found at

http://www.maxwell.vrac.puc-

rio.br/series.php?tipBusca=dados&nrseqser=5. Figure 2

shows screen shots of some Learning Objects in EE.

Fig. 2. Learning Objects with a a small simulator, videos and hypermedia.

When the course was switched to b-learning it was necessary to have a resource to guide the student from one topic to the

other, to suggest activities, to link to other contents (internal

and external links) and to present the main topics. This

resource is called Roteiro (Course Guide) and also offers 23

short videos that address specific topics. The presentation

materials used in the videos are available for students too.

Figures 3 shows screen shots of the Roteiro. The Roteiro

allows students a preliminary study of the topic before class

so that it is used for discussions and questions on the subject,

and also freeing time to solve problems.

Fig. 3. Roteiro – table of contents, a definition, a video and

an activity.

These resources started being developed before 2015 but they

were not discontinued; new items are added every semester.

3. A NEW TYPE OF COURSEWARE DEVELOPED IN AND AFTER 2015

In 2013, Costa-Castello, Guzman, Berenguel and Dormido wrote: “Many concepts have complex visual representations

which can not sufficiently be explored through the normal

classroom experience. For these reasons, a need arises for a

set of applications which provide students the opportunity to

visually and interactively explore the classroom concepts

without use of pen and paper.” (Costa-Castello, 2013).

Options of interactive tools have been presented by many authors, as for example the use of Augmented Reality

(Restivo, 2014). Ariza (2015) introduced an interactive

platform that integrates hardware and software to teach

control systems. An interesting use of low cost technology is

the implementation of an artifact that each student may have

and take to home to experiment with control systems (Taylor

at al., 2013). These works are based on the knowledge that

experimentation, even if virtual or numerical, leads to a better

understanding of concepts.

Engineering courses have been users of MATLAB® for many years. The Electrical Engineering Department of PUC-Rio

has this software installed in its labs. Students are proficient

in the use of this product. But to use it students must be at

one of the labs during office hours.

Scilab (http://www.scilab.org/) is a free and open source software for numerical computations that can be used to solve

problems the same way MATLAB® can. Scilab was used to

solve electronics problems (Campos, 2010) in an

undergraduate course and was integrated to Moodle, the free

and open LMS – Learning Management System.

In order to enhance the interactivity of the online resources for the b-learning course, a decision was made to develop

learning objects using Scilab and make them available from

the Maxwell System. This new set is called Simulações em

Engenharia Elétrica (Simulations in Electrical Engineeering)

and can be found at http://www.maxwell.vrac.puc-

rio.br/series.php?tipBusca=dados&nrseqser=12. The

following subsections address this new set.

3.1 Development Strategy

The decision was to focus on Control Systems, though there is a plan to develop for Signals & Systems and Electric &

Electronic Circuits too. The development steps were:

Objects to support topics of the syllabus:

Nyquist Stability Criterium – one object with 7 exercises and one simulator was developed. In the simulator the

user can define the transfer functions and in the exercises

only the parameters.

Root Locus Plot – one object with 8 exercises and one simulator was developed. In the simulator the user can

define the transfer functions and in the exercises only the

parameters.

Bode Plot – one object with the RL, RC and RLC circuits, and the spring-mass-damper system.

Objects with systems that are analyzed and/or controlled

by different methods:

Inverted Pendulum – one object with the computation of the transfer function and the state-space model, the

stabilization using the PID controller, the adjustment of

the controller using the Root Locus Plot and control

using the State Feedback Controller.

DC Motor – one object with the computation of the

transfer function and the state-space model, the

stabilization using the PID controller, the adjustment of the controller using the Root Locus Plot and control

using the State Feedback Controller.

Analysis of the RLC Circuit – one object with the Root

Locus Plot, the Bode Diagram, the Nyquist Stability Criterium and transient responses due to the impulse, the

step and the ramp functions; R is the variable parameter.

There are situations in which the students must practice the

methods they are studying – for this need, step one implemented objects for specific methods. For each, transfer

functions were presented and the students could change the

parameters to observe the differences in the results. For the

Nyquist Stability Criterium and the Root Locus Plot an

option for the studeents to choose the transfer functions

themselves is available. The second step focused a systemic

approach to analyze and control a system.

Currently, three systems are under development: spring-mass-damper systems with 1, 2 and 4 degrees of freedom.

This work is being supervised by a faculty of Mechanical

Engineering.

Figure 4 shows some screen shots of the Inverted Pendulum object.

Fig. 4. Inverted pendulum.

3.2 The Integration of Scilab with the Maxwell System

Scilab was installed on a server that communicates with the Maxwell System. This communication works as follows:

The developers create the Scilab programs (.sci) that

implement the systems/methods of each object and also

the textual and image files (.doc) that “wrap” the object.

The two sets of digital files are sent to the Maxwell

System technical staff that integrate the Scilab code and

the text into a .php program. The interfaces are in html.

This new object is sent to the information staff to describe and upload into the system. This .php program

is stored on the objects server of the system.

When a user accesses one of the objects, the .php program places a request to the Scilab server that

executes the code.

Once the code is executed, the result is turned into an image and returned to the .php program.

The .php program displays the result to the user.

Some objects execute multiple functions and so send multiple

requests to Scilab generating multiple return images.

3.3 The Developers of the Scilab Modules

The Scilab modules have been developed by undergraduate students of Controls and Automation, and Electrical

Engineering – they propose the problems, define the systems

and generate the Scilab code. They also write the theoretical

explanations that introduce the problems. The programming

of the objects , i.e., the integration of all parts, is done by the

technical staff. Faculty guide and supervise the students.

4. THE USE OF THE SIMULATORS IN THE B-LEARNING COURSE IN 2015

The Controls & Servomechanisms course is taught in the b-learning mode, so students use the Course Guide to prepare

for the traditional face-to-face sessions – they use the text

book, online courseware and/or other resources too.

The traditional face-to-face sessions start with doubts and discussions; it is supposed that students previously got to

know the topics. Next, students are encouraged to use the

ICT resources developed for the course. Faculty assign

homework that requires the use of simulators. They are used

in class too. The simulations play an important role, since

students can modify the system parameters and/or models and/or input functions and see what happens with the system

behavior. This allows the students to understand the impacts

of the changes. They yield graphic results and are very fast.

In addition to being an important tool for learning, simulators are also handy to the teacher since time consuming

blackboard drawings are not necessary anymore. Time can be

spent discussing and/or solving additional problems.

The simulators stimulate the students curiosity and present a more “real world” application, linking theoretical aspects to

application. An example is the inverted pendulum simulator

that allows the visualization the concepts of stability and of

two types of classic controllers, verifying their limitations

and differences in mathematical modeling.

Simulators were used for the first time in the second semester of 2015. So far there is not a formal evaluation on how

students react to them. Informal interaction with students

yielded the information that they enjoy using them and think

that a better understanding of system behavior is achieved.

An important aspect of the use of the simulators can be observed from the system usage statistics – the uses of

specific simulators increased along the semester according to

the weeks when the topics were addressed. This happened not

only during the traditional sessions but in other days of the

week, indicating individual study.

At last, the use of simulators stimulates the students to search several values for the simulation, observing the system

behavior and the differences of performance for each

controller and the difficulties in tuning each controller.

5. COMMENTS AND NEXT STEPS

The first impression on the use of the simulators by the

students was quite positive. This was observed by the faculty who taught the course (the second author). The other

resources had been around for a long time and students had

been using them. This is an encouragement to follow the next

steps which are divided in two groups:

Resource development

Concerning the simulators, the next steps are to keep

developing new objects using Scilab. Besides the three that

are under implementation, an airplane system and a watercraft system are planned. The objective is to keep this

collection growing the same way the collection of Learning

Objects in Electrical Engineering is. Concerning the

Interactive Books, currently implemented in Adobe Flash, the

plan is to convert all to html 5.

Though the focus of this work is Control Systems, it is important to mention that simulations will be developed to

support the Signals & Systems and the Electric & Electronic

Circuits courses too. Many objects can be shared due to the

common concepts and methods that these courses have.

All learning resources are created in Portuguese and the simulator objects are currently being translated into English.

They are in open access and this will be useful.

In order to bring the “real world feel” to the ICT supported tools set, a Remote Lab in Control Systems is planned too. It

will allow students to work when and where they can.

Resource usage

Currently, there is a wide variety of online resources

available to support the b-learning course. In the first semester of 2016, a questionnaire will be submitted to

students so they can rate different aspects of each and also

guide enhancements and future developments.

6. THIS DEMO

This demo has two complementary objectives:

Present the integrated set of resources that support the b-learning mode of the Control Systems course

Controls & Servomechanisms has been taught in the b-learning mode since 2014.2 – this means for three semesters.

To switch to this mode it was necessary not only to have

many digital resources but also on integrate them. This

mission is a function of the Roteiro and also of Sala Virtual

(Virtual Room). Sala Virtual is the environment of the LMS

side of the Maxwell System used to deploy distance and b-

learning courses. Sala Virtual yields access to the course agenda, to grades, the communication tools (chat, discussion

forum, bulletin board) and to the persons in the course

(students, faculty, TAs). The integration covers:

Notas de Aula (Class Notes) – 4 volumes of topics on the syllabus and one annex with complementary topics. The

annex was written by 9 students as a contribution to the

course. All are in .pdf format for linear reading and serve

to complement the text book.

Estudo Orientado (Study Guide) – one volume with suggested exercises on all the topics of the syllabus

grouped by topic; each has an introduction. It is in .pdf

format for linear reading.

Files with the presentations in the 23 videos of the Roteiro. All are in .pdf format for linear reading.

Livro Interativo de Controles e Servomecanismos – this

book was presented in section 2.

Objetos Educacionais em EE – this set LOs was

presented in section 2.

Simulações em Engenharia Elétrica – this set of LOs was presented in section 3.

During the demo, access to the Sala Virtual and the Roteiro will be available. They are all in Brazilian Portuguese.

Present each type of interactive resource

This is the main part of the demo since the session is on Interactive Demonstrations. It is important to remark that all

the interactive resources are in open access. They are:

Livro Interativo de Controles e Servomecanismos – the title specifies that the book is interactive. All exercises

are interactive and have the objective of allowing

students to check the understanding and the mastering of

the methods by themselves. The book, as the other two,

is in Brazilian Portuguese but it has had accesses from 22

countries since it was launched in Jan.2010 (until

Feb.2016). The total number of accesses in 6 years was

over 13,000 and over 1,600 came from countries that do

not have Portuguese as an official language.

Objetos Educacionais em EE – this set of 44 LOs contains 7 items that are interactive, 3 that have very

simple quizzes and 11 with videos. All LOs are in

Brazilian Portuguese and have had accesses from 28

since the series started in Aug.2012 (until Feb.2016).

The total number of accesses (to the whole collection) in 3.5 years was over 6,700 and over 1,500 came from

countries that do not have Portuguese as an official

language.

Simulações em Engenharia Elétrica – this set contains 6 items (33 simulating options) in Control Systems and

one in Signals & Systems, all of that are interactive.

Three additional objects (planned 12 simulations

options) are under development. As mentioned, all

objects are originally implemented in Brazilian

Portuguese and are currently being translated into

English. The accesses to these objects deserve a special

comment. Early in the project, the months of May to

Jul.15, the system had counted 967 accesses coming

from Brazil and 36 accesses coming from other countries

(USA, Panama, Croatia and others). After the inclusion

of this resource in the classroom activities, from Aug to

Dec.2015, there were 4,811 accesses from Brazil only

(which shows the interest of students in the use of the

objects) and 154 accesses coming from other countries

(USA, Portugal, Panama, Croatia and others). The

simulations have widely been used by students after

made available. These data confirm the success of the project and stimulate the team to keep adding objects to

the collection. But it also indicates that accesses have

grown because more objects have been made available

and that the school term runs from Aug to Dec. Other

interesting fact is that accesses from other countries are

still logged by the system; this is the motivation behind

translating the objects to English so that more

international students can use them. Access statistics can

be seen at http://www.maxwell.vrac.puc-

rio.br/Esta_serie_anopais.php.

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learning and teaching control systems, Proceedings of

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Campos, D., Dias, N., Dias, A. and Ferreira, H. (2010).

Introducing Numerical Analysis Tools in Engineering. A

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ICERI 2010 – The 3rd International Conference of Education, Research and Innovation, pp. 5178-5184.

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